1. Field of the Invention
The present invention relates to cases for retaining disks therein. More particularly, the present invention relates to storage cases for securely retaining compact disks (CD), digital-video (or digital versatile) disks (DVD), and other mass storage devices therein. Still more particularly, the present invention relates to such storage cases including means for fixing the disk in place within the case. The present invention relates to a disk storage case having a pivotal flap for removably retaining the disk thereon.
2. Description of the Prior Art
The proliferation of optically readable mass storage media, such as CDs, computer Read Only Memory (ROM) disks, and, more recently, DVDs, has generated the need for relatively inexpensive cases for safely storing such disks therein. The most popular standard case for CDs is the jewel case, a transparent hinged three-part structure designed to retain the disk within. The jewel case has essentially become the industry standard for CDs. Its design has been used to define a portion of the CD manufacturing and packaging process. Specifically, the automated equipment used to form and enclose CDs in a case having informational, marketing, etc., graphical materials inserted therein, is designed to fit such materials within the faces of the case, and to fit the completed CD onto a stationary hub that fixes the CD in place within the case.
For the most part, the standard CD jewel cases are formed of three parts--two open-faced frames hingedly connected together, and a hub plate having a centered hub designed to fit within the inside diameter of the CD center hole. One of the frames has two opposing sidewalls, each of which has one or more tabs for retaining informational booklets, marketing booklets, or the like, and a transparent frame face for observing such materials therethrough. Each of the opposing sidewalls of that frame also includes a corresponding pivot nub for pivotal coupling to the second frame. The second frame of the standard existing jewel case includes a pair of opposing sidewalls, a pair of opposing endwalls, and a transparent frame face. It is to be noted that the frame faces of the respective open-faced frames define the length and width of the jewel case. The second frame is designed to retain therein graphical materials observable through the transparent frame face and through the transparent endwalls. The second frame includes means for removably fixing the hub plate therein, and its sidewalls have opposing corresponding indentations for receiving the nubs of the sidewalls of the first frame for pivotal movement thereof.
Different jewel cases manufactured by different suppliers may have hub plates of different designs. For the most part, however, they include a round depression sized slightly larger than the CD within which the CD sits. A relatively flexible rosette or hub rises from the centered of the depression and is designed to be of about the same size as the inside diameter of the center hole of the CD. The hub is typically designed to have some give such that when the CD is positioned in the depression and on the hub, there is a tight fit between the hub and the CD. In this way, the CD is supposed to remain within the depression of the hub plate until the user pops the CD off of the hub in a manner well known to most of the general population.
Unfortunately, in the automated process of making and packaging CDs, as with most automated manufacturing processes, there are many variables than can result in product outcome vagaries. Two areas of concern in regard to the present invention relate to the manufacture of the hub and the manufacture of the CD. Specifically, the hub to which the CD is removably joined may vary in dimensions as a function of the batch of material used to make the hub and its associated plate, the rate at which the hub plate is processed in the molding equipment and variability of the tools used to form the hub. Similarly, the CD manufacturing process and the process of moving the CD through an automated packaging process is a complex one. The CD is formed by first creating an emulsion-based mold having formed therein pits and peaks used to establish specific optically readable variations corresponding to desired electrical signals. A CD forming material, such as polycarbonate, for example, is then applied to the mold so as to create the CD structure.
DVDs are formed in a similar manner; that is, an emulsion-based mold is first created with the surface variations (pits and peaks) used to establish mirror-image peaks and pits in the surface of material that becomes the DVD. However, in order to increase the storage capacity of the storage medium, a pair of molded disks are joined together using a bonding material or mechanism suitable for the particular material used to form the disks. The effect, then, for a CD or a DVD is to create one or two layers of material designed to allow the passage of light therethrough on to the modified surface for reading of the variations corresponding to digital signals.
Clearly, given the complexity of the process, there are ranges of hub dimensions and CD or DVD aperture diameters. As a result, it is not uncommon for these disks either to be too loosely or too tightly coupled to the hub. That is, in those instances where the hub diameter is slightly smaller than nominal and the aperture inside diameter is slightly larger than normal, the disk may slip off the hub and fall unexpectedly out of the container or case upon opening. Alternatively, and more commonly, the hub diameter is slightly larger, the aperture is slightly smaller, or a combination of the two, and the disk fits tightly on the hub. In that situation, the user must exert considerable energy and cause a bending of the disk in order to pop it off the hub. This flexing of the disk can cause crazing of the disk material, as well as separation of joined disks in the case of DVDs. Such forms of damage to the structure of the disk will result in misreading of the intended surface variations, rendering the disk unusable. The effects of structural damage caused by bending of the disk are magnified as digital signals are generated in double and greater densities (double-density disks) for a given surface area, and when such surface variations are applied on both surfaces of the disk (double-sided disks). Further, for the two-layer disk structures, the bending can cause a shifting of those layers with respect to one another. This can lead to the two being out of concentricity with one another, thereby affecting the aperture dimensions and causing surface variation misreadings.
One recognized solution to the problem of forced bending was described by Gelardi et al. in U.S. Pat. No. 4,793,480. Gelardi teaches a disk storage container having a pivotal tongue on which the disk resides when retained in the container. When the container is opened, the tongue pivots outwardly so as to "present" the disk to the user. As with the prior standard CD containers, the Gelardi structure is formed of four components, the base, the pivotable lid that encloses the CD when clamped onto the base, and a CD hub plate, and a tongue that detachably connects to the base and the lid. The tongue is formed of a plurality of pieces and does pivot, but only a limited distance, away from the base when the lid is opened.
While the tongue of the Gelardi container provides a desirable solution to the problem of the suitability of the fit between the hub and the CD, there are several deficiencies in that design that make it less than commercially desirable. First, the Gelardi container does not lend itself to the standard automated disk packaging processes in existence. Specifically, the pivotal disk holder is fixed to the base and to the lid in a manner that permits it to move up to a limited angle away from the base. The maximum distance that the holder moves away from the base is insufficient to allow standard automated graphics insertion equipment to place information materials into the base of the container. Therefore, in order for the Gelardi container to be viable in large-scale processing, the processing equipment would have to be modified, or the holder removed from the base-to-lid coupling, the informational materials inserted in the base, and then the holder re-applied to the base-lid coupling. Such a significant modification to the process is not possible.
Secondly, the cost to manufacture the relatively complex Gelardi container renders it difficult to provide in a mass-market environment. That is, the Gelardi container is designed to be formed of at least four separate pieces, each of which must be formed separately and then all fit together. The cost effectiveness of creating a commercially viable product of multiple parts is generally compromised as a function of the number of parts, the variability of their dimensions during fabrication, and with the increase of possible failure at the multiple connection locations.
Finally, the interface coupling between the lid and the base of the Gelardi container limits the extent to which the lid may be opened away from the base. Specifically, the lid may not pass beyond 180.degree. away from the base. While this is ordinarily sufficient in most automated disk packaging processes, a disk case having the ability to rotate the lid beyond that range would provide greater flexibility for the disk-packaging manufacturer if desired. That is, it may be desirable to be able to pivot the lid more than 180.degree. away from the base in order to increase the automated processing options available to the disk packager.
Relatedly, it has been observed that some disk storage containers are designed in a manner such that the lid may be separated from the base fairly easily, particularly under expected consumer usage. Once the lid has been removed, it can be difficult for the user to re-apply it and, in some instances, may not attempt to, thereby exposing the disk retained within to a greater potential for damage. Further, the material typically used to form the storage cases is made of polycarbonate, as earlier noted. Unfortunately, this transparent material is quite brittle and can either crack under a variety of stress conditions--such as by banging against a fixed surface, or by being dropped. In addition, even if the brittle case does not fail, its rigidity can translate impact conditions directly to the disk contained therein, thereby causing its failure. It would be desirable to have a disk case that can withstand high-stress loading and that can protect, to a degree, the disk under such conditions.
As earlier noted, there are a variety of types of mass storage structures, other than the ubiquitous 640 megabyte CD, used to retain massive amounts of information on a relatively small medium. Increasingly, the digital-video (or digital versatile) disk (DVD) storage structures have been employed in order to store much greater quantities of data--on the order of 17 gigabytes or more. This has enabled the application of relatively complex multimedia presentations, such as full-length feature films, for example, onto laser readable materials. It is well known that such storage provides for much better information presentation than conventional tape-based cassette. In addition, the DVD is generally a more robust medium than tape.
With the introduction of DVDs, there has yet to be established a convention in regard to the holders and storage containers for such disks. As a result, there exists a wide array of DVD containers and cases. Some are similar to conventional CD containers in that they come in three parts, the base, the lid and the removable hub plate. Others come as one or two-piece units with various forms of lid capturing mechanisms as well as various types of graphics retention devices. All come with some form of disk-retaining recess having at its center a hub for coupling to the inside diameter of the disk. Of course, with such pressure-fit hub-based designs there remains the concern of the integrity of the fit between the hub and the disk. This is of concern in the case of a too-tight fit between the disk and the hub, particularly, for a double-density and/or double-sided disk having many more pits and peaks subject to structural damage upon bending of the disk to remove it from the hub. Apart from that, it is not particularly desirable to have a variety of disk containers as it makes it much more difficult to establish standardized disk packaging equipment and processes.
Therefore, what is needed is a container for mass-media storage disks that may be used in conventional automated disk packaging processes with limited modifications to existing automation movements. What is also needed is a disk container that provides for adequate retention of the disk within the container but without causing undue stress on the disk during the process of removing it from the container. Further, what is needed is a disk container that is relatively inexpensive to produce and that is formed of a minimal number of parts easily coupled together. Still further, what is needed is such a disk container that is designed to present the disk for easy removal and that is formed of a material of improved pliability as compared to existing disk cases. Also, what is needed is a disk container having a lid-and-base arrangement that limits the separation of those components under expected use conditions.